Sebastian Copeland is a photographer and environmental activist who's led several successful expeditions in the Canadian Arctic.

On one recent journey, he captured a devastating photo of an emaciated polar bear corpse in northern Nunavut. Copeland believes the polar bear "likely starved to death," he told BuzzFeed Canada.

Sebastian Copeland for Arctica: The Vanishing North (teNeues 2015)

Copeland estimates the bear was about two years old, so disease or sickness was unlikely. He also observed that there were "no blood markings" and "rear-end markings consistent of diarrhea." Inuit people have also told him they've noticed large migrations of polar bears out of the area.

Even though he cannot claim with 100% certainty, contrary to some reports, his "estimation is that it's highly likely it has to do with climate change," he said.

While there's no definitive way to tell unless there is an autopsy, reports of polar bear fatalities due to starvation have increased in many areas, says one scientist.

Jonathan Hayward / The Canadian Press

Andrew Derocher is a professor at the University of Alberta who has been studying polar bears for 32 years. He told BuzzFeed Canada that although it's hard to put "real context around [the photo]," it's rousing conversations of climate change because it's become a more pressing issue.

"Collectively, as polar bear scientists, we are getting more reports and seeing more cases of [starvation]," he said. "Before, people would have gone, 'oh there’s a dead polar bear.' Now it’s a much bigger issue, and more people are studying this, we get more of this type of information."

Less ice means polar bears expend more energy in the process to survive and hunt their prey.

Ilya Naymushin / Reuters

Derocher explains: "Starvation is one of the two mechanisms of population decline for polar bears. Less ice means the bears are less able to gain the energy they need to survive periods without access to prey. The second mechanism of population decline is related to lower reproductive success. When you add both lower survival and lower reproduction, we see declines in population size which we are seeing in some areas."

But Derocher iterates we can't draw one-equals conclusions from a single photo — we have to look at larger data sets to understand how ice change is affecting polar bears, and it is affecting polar bears.

"We can’t say in this instance it is because of starvation — it could be an injury, maybe rabies, or another form of disease," he said. "But we are seeing more polar bears starving to death in the Canadian Arctic. Starvation is the main cause."